The present invention relates to the field of warning or alerting apparatus for protection against robbery.
In many areas of the country, particularly in large metropolitan cities and especially during nighttime hours, taxicabs and taxicab drivers have been subject to unusually high incidence of robberies. Further, many of these robberies have resulted in the injury and frequently the death of the taxicab driver.
Incidentally, a number of specialized warning systems have been proposed heretofore, see U.S. Pat. Nos. 2,979,706; 4,020,477; 4,027,276; 4,032,848, and 4,057,790. However, none of these systems are suitable for the protection of taxicabs and taxicab drivers.
Accordingly, a principal object of the present invention is to provide an inexpensive and practical robbery alerting system for taxicabs, and one which is compatible with existing radio equipment, and which does not alert the robber to the fact that the system has been put into operation.